The present invention relates generally to E1 timeslots which go unused when T1 payloads are transported on E1 frames. More particularly, the present invention relates to an apparatus which enables a customer to transport data utilizing up to 7 channels which frequently go unused when 24 channels of unframed T1 data are transported utilizing 24 of the 32 channels available through E1.
In Europe, the most popular standard for transmitting digital voice data is known as E1. E1 was devised by the International Telecommunications Union-Telecommunication Standardization Sector (ITU-T). The name E1 was given by the Conference of European Postal and Telecommunication Administration (CEPT). In accordance with the E1 standard, 32 standardized 64 Kbps channels (also referred to herein as xe2x80x9ctimeslotsxe2x80x9d) carry digital data at a rate of 2.048 Mbps. In the United States, the most popular standard for transmitting digital voice data is known as T1. T1 was introduced by the Bell System in the 1960""s. In accordance with the T1 standard, 24 standardized 64 Kbps channels carry digital data at a rate of 1.544 Mbps.
Frequently, customers in Europe wish to transport T1 data to the United States. These customers typically provision E1 service to their premises and transport the 24 channel T1 payload to the United States utilizing 24 of the 32 E1 channels provisioned to their premises. One of the 8 remaining E1 channels is utilized for framing. Thus, up to 7 E1 channels which might be utilized to transport data go unused when the European customer transports T1 data utilizing E1.
In view of the above, it can be appreciated that there is a need for an apparatus which solves the above described problems.
The present invention provides an apparatus for multiplexing 24 channels of unframed T1 data onto an E1 frame. According to one embodiment of the present invention, a multiplexer receives 24 64 Kbps channels of unframed T1 data at one interface and up to 7 64 Kbps channels of additional data at a second interface. The data received at these two interfaces is multiplexed into E1 format and output at a third interface.